diff -r 7ef7a5fbb85d -r 072ec8120958 lemon/capacity_scaling.h
--- a/lemon/capacity_scaling.h	Fri Nov 13 00:37:55 2009 +0100
+++ b/lemon/capacity_scaling.h	Fri Nov 13 00:39:28 2009 +0100
@@ -681,7 +681,7 @@
 
     // Initialize the algorithm
     ProblemType init() {
-      if (_node_num == 0) return INFEASIBLE;
+      if (_node_num <= 1) return INFEASIBLE;
 
       // Check the sum of supply values
       _sum_supply = 0;